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The Spectrum of the Planetary Nebula IC 418
Feibelman, Walter A.; Hyung, Siek; Aller, Lawrence H.
A detailed high spectral resolution study of the spectrum of IC 418 is made for the region 3650A to 10050A, using the Hamilton echelle spectrograph of Lick Observatory, and of the UV spectral region with archival International Ultraviolet Explorer (IUE) data. From the high resolution images in both the near- and mid-infrared, Hora et al. (1993) sh…
Follow-Up Observations of the Remarkable Double-Degenerate Binary LB 11146
Glenn, Jason; Liebert, James; Schmidt, Gary D.
LB 11146 is a double-degenerate binary system consisting of two white dwarfs of very similar mass and surface temperature, but widely different magnetic field strengths. In an attempt to contrain the possible evolutionary tracks of the object, time-series H-alpha spectroscopy and the DA component was obtained with a time resolution as high as 11.5…
X-ray Planetary Nebulae
Feibelman, Walter A.
A study of IUE archival low-dispersion spectra was conducted in an attempt to correlate the C IV/He II and C III]/C IV emission line ratios as indicators of x-ray emission in planetary nebulae. The presence of P Cygni lines revealed a strong correlation for planetaries known to exhibit x-ray emission. Of the twelve planetaries definitely known to …
On Planetary-Nebula Nuclei of the Spectral Type `Continuous'
Feibelman, Walter A.
A detailed reexamination of existing and new IUE low- and high-resolution spectra, plus a search of recent literature, shows that for most of the central stars of planetary nebulae the spectral classification previously called "continuous type" does not really exist. The stellar continua show primarily photospheric absorption features of N V, O V,…
MG II Chromospheric-Emission Dating of HR 1614 Moving-Group Stars
Smith, Graeme H.; Hufnagel, Beth
A 2800 A Mg II line index (Mg II) that is sensitive to chromospheric activity has been measured from International Ultraviolet Explorer spectra of a sample of eight HR 1614 moving-group dwarfs. All of these dwarfs have values of I(Mg II) indicative of ages >= 3 Gyr. The relatively old ages of these dwarfs, togther with their similar and peculia…
HL Canis Majoris in Preoutburst and SS Cygni -- The Interoutburst Disk Instability
Garnavich, P. M.; Kaitchuck, R. H.; Dinshaw, N. +2 more
SS Cygni and HL Canis Majoris were observed by IUE for three consecutive nights in November of 1992. During the first two nights, simultaneous photometric ground-based observations of SS Cyg were made at the Ball State University Observatory. Observations of SS Cyg and HL CMa were also obtained simultaneously with the 90-inch telescope at the Stew…
Optical and Ultraviolet Spectroscopy of VW Hydri
Saygac, A. Talat
Spectra of the SU UMa type dwarf nova VW Hydri obtained in the visual (lambda-lambda 3400-7200A) and ultraviolet (lambda-lambda 1150-3200A) spectral regions are presented. During the quiescent phase, visual spectra of VW Hydri present strong double-peaked Balmer emission lines. In addition, He I lambda 5876, Fe II lambda-lambda 4233, 5196 He I lam…